Sustainable benefits of geothermal energy

A recent study from the University of Technology Sydney (UTS) has found that homes at a sustainable community in Western Sydney use 21% less electricity than comparable nearby suburbs, due to geothermal technology.

The $1.64 million project known as the Fairwater Living Laboratory was funded by the Australian Renewable Energy Agency (ARENA), Frasers Property Australia and the NSW Office of Energy and Climate Change.

Led by Professor Leena Thomas, the study examined the effects of ground source heat pumps on the 750 homes at the Fairwater community by Frasers Property Australia. It found that when installed at scale and at the beginning of the building process, geothermal technology can be both a profitable and environmentally beneficial addition to a home.

Ground source heat pumps use the stable ambient temperature below ground to heat and cool homes. In summer the units take heat from inside the home and transfer it via a series of underground pipes to the ground for cooling before returning it to the home. In winter they take natural heat from the ground and reverse the process.

“The research demonstrated clear energy benefits from geothermal technology and high ratings for comfort in the Fairwater homes,” Thomas said.

“An overwhelming majority of residents at Fairwater also reported that living in the precinct has had a positive effect on their health and wellbeing.”

The project, which spanned three years from September 2019 to August 2021, and encompassed the Sydney COVID lockdowns, also found that the demand reduction aspects of the geothermal technology had the potential to ‘smooth out’ electricity grid usage, which could help avoid spikes that can lead to blackouts and power cuts in extreme weather.

Fairwater homes recorded an average of 3 kW of avoided power demand per household during critical peak events.

An integrated approach is key to reaching net zero

While the study focused on the benefits of the ground source heat pumps, it also looked at the other environmentally sustainable aspects of Fairwater, including its light-coloured roofs.

It found that the roofs already produced a cooling effect of three to four degrees. As trees at Fairwater mature it is expected the ambient temperatures in the community will reduce even further.

“Our findings highlight that an integrated precinct-based approach for incorporating sustainability and energy-efficient technologies when combined with an understanding of occupant practices offers the best pathway for decarbonisation and getting beyond net zero,” Thomas said.

“This has been such an interesting project to support and watch unfold,” said Cameron Jackson, General Manager Development NSW, Frasers Property Australia.

“We were confident the installation of geothermal heating and cooling technology in our Fairwater homes would help our customers reduce their energy consumption and their bills, and now we have confirmation of that,” he said.

“We will use the findings of this groundbreaking study to guide us on our pathway to net zero.”

The study found installing geothermal technology at scale at Fairwater added additional upfront cost to the construction; however, combined with other environmentally friendly features of Fairwater homes, it contributed a cost saving to the users and value to the properties at completion.

Future benefits

Belinda Whelan, Director of Strategic Projects, Climate-KIC Australia, said the study would provide governments and the property industry with solid information on which to base their geothermal decision-making.

“The built environment sector in Australia has a really important role to play in helping Australia meet its net-zero ambitions. Studies like Fairwater provide policymakers and the property sector with deep insight and data to guide informed decision-making to make rapid change at scale,” she said.

The Fairwater Living Laboratory project drew on multidisciplinary expertise from UTS’s faculties of Design, Architecture and Building; Science; and Health, along with its Institute of Sustainable Futures. It was undertaken in association with Climate-KIC Australia and Curtin University.

Image credit: iStock.com/Nastco